public class Array<E> {
    private E[] data;
    private int size;

    public Array(int capacity) {
        data = (E[])new Object[capacity];
        size = 0;
    }

    public Array() {
        this(10);
    }

    public Array(E[] arr) {
        data = (E[]) new Object[arr.length];
        for (int i = 0; i < arr.length; i++)
            data[i] = arr[i];
        size = arr.length;
    }

    public int getSize() {
        return size;
    }

    public int getCapacity() {
        return data.length;
    }

    public boolean isEmpty() {
        return size == 0;
    }

    public void addFirst(E e) {
        add(0, e);
    }

    public void addLast(E e) {
        add(size, e);
    }

    public void add(int index, E e) {
        if (index < 0 || index >size)
            throw new IllegalArgumentException("Add failed. Require index >= 0 and index <= size.");
        if (size == data.length)
            resize(2 * data.length);
        for (int i = size - 1; i >= index; i--)
            data[i + 1] = data[i];
        data[index] = e;
        size++;
    }

    public E get(int index) {
        if (index < 0 || index >= size)
            throw new IllegalArgumentException("Get failed. Index is illegal.");
        return data[index];
    }

    public E getLast() {
        return get(size - 1);
    }

    public E getFirst() {
        return get(0);
    }

    public void set(int index, E val) {
        if (index < 0 || index >= size)
            throw new IllegalArgumentException("Set failed. Index is illegal.");
        data[index] = val;
    }

    public boolean contains(E val) {
        for (int i = 0; i < size; i++) {
            if (data[i].equals(val))
                return true;
        }
        return false;
    }

    public int find(E val) {
        for (int i = 0; i < size; i++) {
            if (data[i].equals(val))
                return i;
        }
        return -1;
    }

    public E remove(int index) {
        if (index < 0 || index >= size)
            throw new IllegalArgumentException("Remove failed. Index is illegal.");
        E val = data[index];
        for (int i = index + 1; i < size; i++) {
            data[i - 1] = data[i];
        }
        size--;
        data[size] = null;
        if (size == data.length / 2)
            resize(data.length / 2);
        return val;
    }

    public E removeFirst() {
        return remove(0);
    }

    public E removeLast() {
        return remove(size - 1);
    }

    public void removeElement(E val) {
        int index = find(val);
        if (index != -1)
            remove(index);
    }

    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();
        res.append(String.format("Array size: %d, capacity: %d\n", size, data.length));
        res.append("[");
        for (int i = 0; i < size; i++) {
            res.append(data[i]);
            if (i != size - 1)
                res.append(", ");
        }
        res.append("]");
        return res.toString();
    }

    private void resize(int newCapacity) {
        E[] newArr = (E[]) new Object[newCapacity];
        for (int i = 0; i < size; i++)
            newArr[i] = data[i];
        data = newArr;
    }

    public void swap(int i, int j) {
        if (i < 0 || i >= size || j < 0 || j >= size)
            throw new IllegalArgumentException("Index is illegal.");
        E t = data[i];
        data[i] = data[j];
        data[j] = t;
    }
}